Watertight timepiece case



April 14, 1970 E. PIQUEREZ WA'I'ERTIGHT TIMEPIEVCE CASEl l 2 Sheets-shemz Filed Feb) 25. 1968 United States Patent O 3,505,807 WATERTIGHTTIMEPIECE CASE Ervin Piquerez, 2854 Bassecourt, Switzerland Filed Feb.23, 1968, Ser. No. 707,745 flaims priority, application Switzerland,Feb. 24, 1967, 2,750/67; June 1, 1967, 7,849/67 Int. Cl. G04b 37/ 08U.S. Cl. 58-90 3 Claims ABSTRACT OF THE DISCLOSURE A watertight closurefor a timepiece, such as a wrist watch, is described. Grooves placed inthe casing and the crystal of the watch form a complementary rectangularenclosure in which an elastomeric ring of circular cross section isdeformed, exerting a retaining force and, by virtue of its resiliencyacts as a watertight seal.

This invention relates to Watertight timepieces and means for elfectingsuch watertightness.

It has already been proposed to achieve the watertightness of a crystalhaving an annular part encased on a shoulder of the middle bypositioning a watertight packing placed in a housing formed between thecrystal and the middle by peripheral grooves made in each of these. Thispacking has a suflicent mechanical resistance to ensure the securing ofthe two parts.

In an embodiment of the above type, the joint in its free state isplaced mainly in the housing of the middle, the crystal having only ahollow nick intended for hooking the joint. This hooking is obtained bymeans of the mechanical resistance of the joint, the material used forits manufacture not being or being only slightly elastically deformable,the fastening being obtained to the detriment of the watertightness.

The present invention proposes to remedy this drawback and has for itsobject a Watertight timepiece case in which at least one of the parts,crystal or casing, is encased on the middle with interposition of acoupling engaged in an enclosure formed between said part and the middleby peripheral grooves made in each of these members, this couplingcomprising a ring of elastically deformable material.

The invention also has for its object a process for mounting the partcharacterized by the fact that the ring is compressed at least partiallyinside the groove made in the part before introduction thereof in themiddle in such a way as to give to this ring dimensions substantiallyequal to the lateral dimensions of the opening of the middle.

It also has for object a device for carrying out this processcharacterized by the fact that it comprises a template having inwardlyat least one tubular part having lateral dimensions equal to those ofthe opening of the middle and flaring out at its upper extremity, thewhole in such a way that said ring can be compressed in the groove ofsaid part during axial movement thereof towards the lower extremity ofsaid template and that this part be maintained by said tubular part.

The accompanying drawing represents by way of example variousembodiments of the invention.

FIGURES 1 to 4 are successive cross sectional views of a device forsecuring the crystal fora first embodiment.

FIGURE 5 is a cross sectional view of a device for securng a crystalaccording to another embodiment.

FIGURE 6 is a cross section of a case whose bottom is secured accordingto the process of the invention.

FIGURE 7 is a cross section of a case whose crystal is secured accordingto another modification.

3,505,807 Patented Apr. 14, 1970 In FIGURES 1 to 4, the part having theperipheral grooves is a crystal 1 which during the moulding process, isprovided with an extraction retaining groove 2 and a groove 3. In thecase of a polygonal part, there is provided a rectilinear groove 2 onthe two opposite sides while if the same is a round or an oval piece,this groove can be made along the entire periphery of the part or onlyin certain parts thereof.

The compressible watertight ring 4 is of any cross section and isintroduced in groove 3 which has a substantially rectangular crosssection, these cross sections being substantially equal in order topermit the placing of the ring 4 in the groove 3 by compression.

This compression is obtained during axial movement of part 1 in frame 5.This frame has on its lower part a tubular surface 6 whose dimensionsare equal to those of opening 7 of casing 8. Tubular part 6 is cut atits lower extremity by a plane surface 9 and has at its upper eX-tremity a flared part 10 formed by two arcs of a circle tangent to oneanother, one of them being tangent in addition to tubular part 11 havingdimensions greater than the first.

Casing 8 has on its lateral surface 7 a groove 12 of rectangular crosssection and a shoulder 13 on which rests dial 14.

There can be seen on FIGURES 1 to 4 how ring 4 is compressed in groove 3when crystal 1 is axially moved in frame 5. Once positioned, ring 4remains compressed in the bottom of grooves 3 and 12, which on the onehand ensures watertightness and on the other hand secures the glass inthe center. As can be seen on FIGURE 4, grooves 3 and 12 are slightlyaxially shifted and ring 4 bears against the lower edge of groove 3 andthe upper edge of groove 12 creating two forces of opposite directionsalong double arrow F.

The depth of groove 3 equals about 2/3 of the room necessary for ring 4in order that the latter be driven by the crystal during its extractionby means of a tool engaging in groove 2. Alternatively, in order tomaintain the joint in the groove of the crystal, this joint ispositioned under strong pressure.

In FIGURE 5 is shown another device at a stage of the processcorresponding to that of FIGURE 1 which differentiates thereof by theshape of frame 5 whose opening has a lower part 6 of dimensionscorresponding to those of middle 8 and a flared out upper part 15. Thisframe also has a hollow 16 in which is positioned middle 8, the wholeresting on a support 17. The crystal is pushed in by means of a pushingtool 18. There has also been shown a watertight packing 19 against whichbears the lower edge of crystal 1.

FIGURE 6 shows a timepiece with a reset bottom according to the processof the invention.

FIGURE 7 represents a modification in which it is not necessary to use aframe, the middle itself having an inclined flank 20 permitting tocompress the joint in groove 3 of the crystal when the same is put inplace. In this case, the crystal also has an inclined flank 21 intendedto mask flank 20 of the middle.

As can be seen in the different figures, groove 12 can be rectangular orrounded. The cross section of joint 4 is also of any shape.

What is claimed is:

1. A watertight closure for watches comprising a tubullar annular casingmember having an inner groove of rectangular configuration, adome-shaped crystal member adapted to fit within said casing, saidcrystal having an outer groove of rectangular configuration, both saidgrooves lbeing in complementary position upon insertion of said crystal,an elastomeric ring of circular cross sec- 3 tion adapted to be placedin one of said grooves, said ring upon insertion of said crystal beingdeformed between said grooves into an ellipsoidal shape, its expandingforce serving to retain both said members into firm engaging position and forming a fluid-tight sea] between said members.

2. A watertight closure for watches in accordance with claim 1 whereinsaid crystal member has a second outer groove serving as anchorage foran instrument in prying apart the assembly.

3. A watertight closure for watches in accordance With claim 1 whereinsaid elastomeric ring is made of rubber.

4 References Cited UNITED STATES PATENTS 2,350,651 6/ 1944 Taubert etal. 58 91 X 2,737,010 3 1956 Piquerez 58-90 FOREIGN PATENTS 245,430 1 1/1946 Switzerland. 394,960 12/ 1965 Switzerland.

RICHARD B. WILKINSON, Primary Exarniner G. H. MILLER, JR., AssistantExaminer

